新型间苯二酚杯芳烃硫脲衍生物对阴离子的识别

通过间苯二酚杯芳烃连续三步反应, 以较高产率合成了分子中连有8个和12个硫脲端基的间苯二酚杯芳烃的酰胺衍生物. 用紫外可见光谱法研究了两个代表性化合物4,6,10,12,16,18,22,24-八[6-(苯基硫脲基)-己氨甲酰基甲氧基]-2,8,14,20-四苯基杯[4]间苯二酚芳烃(THBC)和4,6,10,12,16,18,22,24-八[2-(苯基硫脲基)-1-甲基乙基-1-氨甲酰基甲氧基]-2,8,14,20-四苯基杯[4]间苯二酚芳烃(TPBC), 对各种阴离子(AcO^－, H₂PO₄^－, HSO₄^－, H₂PO₄^2－, C₁₂H₂₅-C₆H₄-SO₃^－, Cr₂O₇^2－, B₄O₇^2－, Cl^－, Br^－)的识别性能, 结果表明它们对AcO^－, H₂PO₄^－, HSO₄^－等阴离子有较好的配位作用, 能形成1∶3的配合物.     

类杯芳烃孔穴桥联双芘分子开关化合物

利用构型可变的分子开关类杯芳烃孔穴化合物(Cavitand)作为母体,合成了2种具有不同臂长的双芘Cavitand化合物.在室温及中性状态下,2种双芘Cavitand化合物均可检验出分子内激基复合物荧光,其中短臂双芘Cavitand化合物的荧光明显强于长臂Cavitand化合物.经三氟乙酸酸化后,2种双芘化合物的分子内激基复合物荧光消失;而继续使用碱中和至中性,则荧光恢复.这个荧光出现-消失-出现的过程验证了Cavitand母体化合物分子构型闭合-打开-闭合可有效调控分子激基复合物荧光开关过程.此外,通过高斯计算模拟了2种化合物的理论分子构型,发现长臂双芘化合物在Cavitand母体构型处于闭合状态时2个芘基团重叠部分较少是其分子内激基复合物荧光较弱的关键原因.     

杯芳烃-卟啉化合物的合成及性质

杯芳烃和卟啉通过共价键连结或者分子间作用力聚集形成的杯芳烃-卟啉化合物在分子识别、分子催化、分子自组装等方面有潜在的用途. 本工作综述了杯芳烃-卟啉化合物的合成及性质.     

杯芳烃-卟啉化合物及其金属配合物的Langmuir-Blodgett膜研究

通过对杯芳烃-卟啉化合物及其锌、钯配合物LB膜的表面压-表面积等温线、紫外可见光谱和傅里叶变换红外光谱的检测,研究了它们在气/液界面和Langmuir-Blodgett膜中的性质,并用量子力学方法优化了杯芳烃-卟啉化合物的构型.结果表明,成膜时3种化合物分子中卟啉环都倾斜地排列在亚相表面,且卟啉环间存在π-π相互作用.连接杯芳烃和卟啉之间的碳氢链在膜性质中起着重要的作用,杯芳烃-卟啉化合物分子中这种碳氢链的有序性小于其锌、钯配合物分子中的这种碳氢链有序性.     

四烷基间苯二酚杯芳烃八[N-(2-吡啶甲基)乙酰胺]的合成和分子结构

为深入开展杯芳烃为骨架的超分子拓扑结构的组装和性能,开展了间苯二酚杯芳烃八取代吡啶酰胺的合成和分子结构的研究。 以四丙基、四己基和四庚基间苯二酚杯芳烃为原料,使用α-氯乙酸甲酯实现O-烃基化,后者在无溶剂条件下与2-氨甲基吡啶反应实现酰胺化,制备了烷基间苯二酚杯芳烃八[N-(2-吡啶甲基)乙酰胺]衍生物。 用X衍射方法测定了四丙基间苯二酚杯芳烃八乙酸甲酯、四丙基以及四己基间苯二酚杯芳烃八[N-(2-吡啶甲基)乙酰胺]的单晶分子结构。 在晶体中,间苯二酚杯芳烃都以全顺式构型存在,在成环的四个间苯二酚单元中,1,3-位的两个间苯二酚单元处于近直立构象,2,4-位的另两个间苯二酚单元处于近平伏构象,而4个烷基皆处于分子的下缘,8个乙酰胺支链伸向分子的外围。     

三氮唑取代杯[4]芳烃配位聚合物的合成与荧光性能

利用四[1-(1, 2, 4-三氮唑基)甲基]间苯二酚杯[4]芳烃配体(TTR4A)在溶剂热的条件下合成了两个配位聚合物,[[Zn₂(TTR4A)(L)₂]·DMF·4H₂O]_n(化合物1) (DMF = N, N-二甲基甲酰胺)和[[Co(TTR4A)Cl₂]·DMA·H₂O]_n (化合物2) (H₂L = 4, 4’-联苯二甲酸) (DMA = N, N-二甲基乙酰胺)。通过单晶X射线衍射方法对这两个配位聚合物的结构进行了确定。利用红外、元素分析、粉末X射线衍射(PXRD)和热重表征手段对化合物1和2进行了表征。在化合物1中,四个L配体连接着四个Zn(Ⅱ)离子形成了环状的Zn₄L₄结构单元,该结构单元进一步地被TTR4A链接形成了一维链状结构。在化合物2中,TTR4A的四个三氮唑基团各连接一个Co(Ⅱ)离子形成二维层状结构。此外,我们对化合物1的荧光性能进行了研究,荧光测定表明固态条件下化合物1发出很强的荧光,并能够选择性地对Fe³⁺、Cr₂O₇²⁻和硝基苯分子产生响应。     

杯芳烃-卟啉化合物及其锌、钯配合物的制备与成膜性能研究

将广泛用作分子构架和分子载体的杯芳烃和卟啉结合,合成了具有更多功能和用途的杯芳烃-卟啉化合物及其锌、钯配合物,并成功地在气/液界面得到它们的单分子膜,并对其成膜性能作了初步的探讨.结果表明,无论是杯芳烃-卟啉化合物还是它的锌、钯配合物均能形成稳定的单分子膜.     

手性杯[4]芳烃氨基醇的合成及自组装

用25,27-二(2-溴乙氧基)-26,28-二羟基-5,11,17,23-四叔丁基杯[4]芳烃与光学纯的(1S,2R)-(+)-2-氨基-1,2-二苯基乙醇合成了手性杯[4]芳烃氨基醇2. 2能在极性的甲醇中组装成二聚体,通过¹H NMR滴定测定其结合常数K_a为34.7 M^-1,并提出了自组装机理.     

磺酰脒基桥连的锌卟啉-富勒烯化合物构型对光诱导电子转移机理的影响

通过"一锅法"多组分偶联反应合成了一种新型磺酰脒基桥连的卟啉-富勒烯化合物ZnP-H-C₆₀. 该化合物具有Z式和E式2种异构体, 其中Z式异构体中含有分子内氢键. 光物理研究结果表明, 2种异构体中的卟啉与富勒烯之间都可以发生光诱导电子转移, 但其相应的电子转移机理却完全不同. 在Z式异构体中, 卟啉或富勒烯被激发后直接发生电荷分离而形成电荷分离态, 其电荷分离机理是通过氢键进行电子传递; 在E式异构体中, 由于卟啉和富勒烯之间存在空间电子相互作用, 被激发后先形成卟啉-富勒烯激基复合物, 再进一步发生电荷分离形成电荷分离态, 电荷分离通过空间电子转移实现.     

通过氢键构筑的含3-硝基邻苯二甲酸的层状超分子化合物

合成了含大量氢键的层状超分子化合物[C₄H₁₂N₂](HL)₂ (I)和[YL(HL)(H₂O)₃]₂•2H₂O (II) (H₂L＝O₂NC₆H₃- (CO₂H)₂, 3-硝基邻苯二甲酸), 并通过元素分析、红外分析和单晶X衍射表征了组成与结构. 化合物I为双质子化哌嗪阳离子和3-硝基邻苯二甲酸氢根阴离子组成的加合物, 阴离子之间靠强烈的O—H…O氢键形成无限链状结构, 同时阴离子链通过N—H…O氢键与阳离子扩展成网状结构, 相邻的网状结构再由分子间弱作用力构筑成层状超分子. 化合物II则是在双核稀土配合物结构单元通过O—H…O氢键构成的网状结构基础上再进一步由层间弱作用力构筑成的层状超分子化合物. 化合物II的网格结构中, 菱形单元空隙里填充的两个结晶水通过氢键将结点上的双核单元更牢固地结合在一起. 化合物I为单斜晶系, P2₁/c空间群, a＝1.3176(3) nm, b＝1.1096(2) nm, c＝0.75950(15) nm, b＝97.14(3)°, V＝1.1017(4) nm³, Z＝4, μ＝0.129 mm^－1, D_c＝1.533 Mg/m³. 化合物II为三斜晶系, P-1空间群, a＝0.81262(16) nm, b＝0.86942(18) nm, c＝1.5011(3) nm, α＝99.84(3)°, β＝91.26(3)°, γ＝104.55(3)°, V＝1.0091(4) nm³, Z＝1, μ＝2.983 mm^－1, D_c＝1.910 Mg/m³.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.